Studying the Earth and the Environment from Space
- Cet article est une traduction de :
- L’observation de la Terre et de l’Environnement
Notes de la rédaction
Excerpts from the Inaugural Lecture 21 March 2013
Source: La lettre, no. 36, May 2013
1We are all used to see images of the Earth’s atmosphere taken by meteorological satellites.
2These images, along with many other observations collected from space, from the ground and within the atmosphere itself, are used to feed models with which meteorologists are able to forecast the weather. Whereas meteorological maps are well known to the public, fewer people know that many other domains relating to the Earth’s environment also benefit from satellites’ constant monitoring. For example, ocean observations from space have now reached a degree of maturity such that, like in meteorology, it is possible to forecast the state of the ocean several days ahead. Space observations also contribute to monitoring climate change by quantifying global warming, continental ice melting and sea level rise. The monitoring of the global water cycle, land use and land use change, deforestation, agricultural crops and natural disasters also increasingly rely on space observations. Finally, satellite data are crucial for the study of the solid Earth, its gravity and magnetic field, its rotation and crustal deformations, particularly in seismic regions.
3The Earth is a complex system, the different components of which (from the innermost part of the globe to its surface envelopes) interact on a broad range of spatial and temporal scales. To describe the global nature of the phenomena concerned, satellites are irreplaceable tools. Their advantages are well known: they offer a global view and a fine spatial resolution. The observations cover regions that are difficult to access, and are carried out virtually continuously or often repeatedly. The measurements are well calibrated and rapidly accessible.
4It is clear that the knowledge acquired over the last few decades thanks to satellites has contributed to changing our outlook on the planet and its environment. It also provides us with a synoptic vision of the global changes affecting the system under the effect of natural phenomena and anthropic pressure, with a wide variety of consequences on human societies. With the progress expected from technology, this is only the dawn of deeper knowledge of the planet. But beyond that, space observations – observations combined with the modelling of the phenomena more generally – also contribute to optimizing the management of some of our vital resources, like water or agricultural ones. The data collected help to validate forecasting the models put at the service of society and decision makers. Their ultimate goal is to manage Planet Earth better, so as to meet the requirements of sustainable development, in other words the preservation of the balances between societal needs, the maintenance of ecosystems and economic efficiency.
This series of lectures will present the current state of knowledge in several domains of the Earth sciences for which space plays an important role: the field of gravity, the rotation and deformations of the Earth, the oceans, the ice sheets and the climate, the global water cycle. We will also discuss certain applications that relate more specifically to the domain of the environment, such as monitoring major disasters, changes in land use, the state of crops and food security, and finally, water resources.
• Inaugural Lecture published by Éditions Fayard and online at www.books.openedition.org/cdf/3286.
• The video of the Inaugural Lecture is available online at www.college-de-france.fr, on the professor's page.
• This Chair is funded by Total.
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Anny Cazenave, « Studying the Earth and the Environment from Space », La lettre du Collège de France [En ligne], 8 | mars 2014, mis en ligne le 11 août 2015, consulté le 24 avril 2017. URL : http://lettre-cdf.revues.org/1999Haut de page
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